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HBase >> mail # user >> Concurrently Reading Still Got Exceptions


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Re: Concurrently Reading Still Got Exceptions
Looks like the issue might be related to HTable:

          at org.apache.hadoop.hbase.client.HTable$ClientScanner.
nextScanner(HTable.java:1167)
          at org.apache.hadoop.hbase.client.HTable$ClientScanner.
next(HTable.java:1296)
          at org.apache.hadoop.hbase.client.HTable$ClientScanner$1.
hasNext(HTable.java:1356)

In newer version of HBase (0.94), you can pass executor to HTable ctor so
that you don't need to use HTablePool:

  public HTable(Configuration conf, final byte[] tableName,
finalExecutorService pool)

Cheers

On Wed, Feb 6, 2013 at 2:27 AM, Bing Li <[EMAIL PROTECTED]> wrote:

> Dear all,
>
> Some exceptions are raised when I concurrently read data from HBase.
> The version of HBase I used is 0.92.0.
>
> I cannot fix the problem. Could you please help me?
>
> Thanks so much!
>
> Best wishes,
> Bing
>
>       Feb 6, 2013 12:21:31 AM
> org.apache.hadoop.hbase.ipc.HBaseClient$Connection run
>       WARNING: Unexpected exception receiving call responses
> java.lang.NullPointerException
>           at
> org.apache.hadoop.hbase.io.HbaseObjectWritable.readObject(HbaseObjectWritable.java:521)
>           at
> org.apache.hadoop.hbase.io.HbaseObjectWritable.readFields(HbaseObjectWritable.java:297)
>           at
> org.apache.hadoop.hbase.ipc.HBaseClient$Connection.receiveResponse(HBaseClient.java:593)
>           at
> org.apache.hadoop.hbase.ipc.HBaseClient$Connection.run(HBaseClient.java:505)
>       Feb 6, 2013 12:21:31 AM
> org.apache.hadoop.hbase.client.ScannerCallable close
>       WARNING: Ignore, probably already closed
>       java.io.IOException: Call to greatfreeweb/127.0.1.1:60020
> failed on local exception: java.io.IOException: Unexpected exception
> receiving call responses
>           at
> org.apache.hadoop.hbase.ipc.HBaseClient.wrapException(HBaseClient.java:934)
>           at
> org.apache.hadoop.hbase.ipc.HBaseClient.call(HBaseClient.java:903)
>           at
> org.apache.hadoop.hbase.ipc.WritableRpcEngine$Invoker.invoke(WritableRpcEngine.java:150)
>           at $Proxy6.close(Unknown Source)
>           at
> org.apache.hadoop.hbase.client.ScannerCallable.close(ScannerCallable.java:112)
>           at
> org.apache.hadoop.hbase.client.ScannerCallable.call(ScannerCallable.java:74)
>           at
> org.apache.hadoop.hbase.client.ScannerCallable.call(ScannerCallable.java:39)
>           at
> org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.getRegionServerWithRetries(HConnectionManager.java:1325)
>           at
> org.apache.hadoop.hbase.client.HTable$ClientScanner.nextScanner(HTable.java:1167)
>           at
> org.apache.hadoop.hbase.client.HTable$ClientScanner.next(HTable.java:1296)
>           at
> org.apache.hadoop.hbase.client.HTable$ClientScanner$1.hasNext(HTable.java:1356)
>           at
> com.greatfree.hbase.rank.NodeRankRetriever.loadNodeGroupNodeRankRowKeys(NodeRankRetriever.java:348)
>           at
> com.greatfree.ranking.PersistNodeGroupNodeRanksThread.run(PersistNodeGroupNodeRanksThread.java:29)
>           at
> java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
>           at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
>           at java.lang.Thread.run(Thread.java:662) Caused by:
> java.io.IOException: Unexpected exception receiving call responses
>           at
> org.apache.hadoop.hbase.ipc.HBaseClient$Connection.run(HBaseClient.java:509)
>       Caused by: java.lang.NullPointerException
>           at
> org.apache.hadoop.hbase.io.HbaseObjectWritable.readObject(HbaseObjectWritable.java:521)
>           at
> org.apache.hadoop.hbase.io.HbaseObjectWritable.readFields(HbaseObjectWritable.java:297)
>           at
> org.apache.hadoop.hbase.ipc.HBaseClient$Connection.receiveResponse(HBaseClient.java:593)
>           at
> org.apache.hadoop.hbase.ipc.HBaseClient$Connection.run(HBaseClient.java:505)
>
> I read data from HBase concurrently with the following code.
>
>         ...
>                 ExecutorService threadPool > Executors.newFixedThreadPool(100);
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB